A generic method for cleaning floor coverings such as carpets and the like is known from DE-AS 1 503 864. In this method a carrier to which a liquid, chemically active cleaning agent has been applied is moved on the floor covering by mechanical force. As carrier serve solid bodies in the form of carrier particles of rubber, plastic material or the like, wetted with liquid cleaning agents, which are continuously directed in a stream to the floor covering to be cleaned, are there mechanically rubbed into the floor covering and then aspired (sucked up) and redirected in a cycle to the starting point. The carrier particles covered with dirt are then cleaned and again wetted with the liquid cleaning agent. A container is provided for the carrier particles which has opening with an adjustable cross section leading to a roller brush. In the direction of its advance, this known machine has behind the roller brush at least one suction line for the extraction of the carrier particles, which is connected with the container via a suction line, a fan and a pressure line.
Although this known system uses solid particles wetted with cleaning fluid in a cycle with an integrated cleaning device, the release of the dirt is still achieved only by mechanical friction of the solid particles on the floor to be cleaned by using a roller brush, so that the machine is heavy and hard to handle. The many machine parts result in high maintenance cost.
The cleaning device consists of two containers arranged one on top of the other, one of them being provided with a rotating screening chamber filled with cleaning fluid, or solvent. After the contaminated solid particles have been fed into the screening chamber filled with cleaning fluid, the cleaning of the solid particles takes place. After the cleaning, the cleaning fluid is discharged into the bottom container and the screening chamber with the solid particles is agitated until they have reached the desired degree of wetness.
This procedure has the disadvantage that the closed cycle has to be interrupted by the replacement of the cleaning fluid. In addition the two containers with the cleaning fluid increase the weight of the machine, which shortens the time one is able to work with the machine. With this machine it is possible to perform only one cleaning step. It is not possible to carry out cleaning, maintenance and polishing in a single work operation.
From U.S. Pat. No. 5,388,304 a system for removing dust from panel-like bodies is known. This dust removing system has a cleaning head with an air discharge chamber, wherein an air jetting slit arranged perpendicularly to the panel-like body is provided. To the air discharge chamber a suction chamber with a suction slit is assigned, which sucks up the air charged with dirt particles exiting the air jetting slit. The dust removal system is equipped with a fan unit and a drive unit, which makes it possible to move the system over the floor in a blast direction.
The air discharge chamber is connected with an air discharge line and the suction chamber with a suction line, so that the air can be guided in a closed cycle.
This known cleaning system is suitable only for dry cleaning on level surfaces. It makes possible the continuous vacuuming of dirt particles into the suction stream, but not the treatment of these surfaces, for instances the application of protective coating on the floor or the polishing of the surfaces so treated.
The U.S. Pat. No. 4,168,562 describes a surface cleaning device for street cleaning and the cleaning of industrial floors by means of high-pressure water jets, to which a central suction opening has been assigned.
Furthermore the DE-G 94 20 172.2 describes a centrifugal blasting device for cleaning large inclined or curved surfaces, particularly for boat outer surfaces, which comprises a mobile blast chamber provided with an opening and with a peripheral spring-provided seal, an impact chamber and a blasting cycle with blast cleaning.
This device is not suited for the gentle treatment of horizontal and vertical surfaces such as building floors and walls.
A large number of nozzle arrangements on vacuum cleaners and other vacuuming devices are known from the prior art. Such nozzles work usually in combination with mechanical aides such as rollers (DE 25 30 126), brushes (DE 36 32 196 A1, DE 44 39 427 A1, DE 41 12 394 A1), rotors (DE 40 39 092 C1), or ultrasonic vibrations devices (DE 195 92 163 C1). None of these known nozzle arrangements is suited for the cleaning, maintenance and polishing of floors and vertical walls in a single operational step.